The present invention relates to intubation devices and, more particularly, to a device and method for inserting and checking the placement of an endotracheal tube in a patient.
Certain types of illness and injury can cause a patient's airway to become blocked or otherwise impaired, preventing adequate oxygenation and ventilation of the patient. When this occurs, prompt corrective action must be taken. Often times, this action requires the placement of an endotracheal tube in the patient's trachea in order to restore or maintain an adequate airway. The process of inserting the tube in the patient is commonly referred to as intubation.
Over the years, various types of intubation devices have been developed for inserting endotracheal tubes in a patient. Perhaps the most commonly used intubation technique is a process known as direct laryngoscopy. In this technique, a device called a laryngoscope is used to actually visualize the upper airway through the patient's mouth during the process of inserting the endotracheal tube. This technique is usually successful in ensuring correct placement of the tube in most patients. However, direct laryngoscopy is not feasible under all circumstances. Indeed, performing intubation on a relaxed, well-prepared patient in a hospital setting is much different than attempting to intubate an accident victim in a moving ambulance, helicopter or on the street itself. Moreover, direct laryngoscopy can have the disadvantage of increasing the risk of dental and soft tissue trauma under certain circumstances.
When intubation is properly performed, regardless of the procedure employed, the inserted end of the endotracheal tube will be positioned in the patient's trachea at a location substantially between the patient's vocal cords and carina. This location has been found to provide the best and most reliable airway management for several reasons. If the tube is not inserted far enough past the vocal cords, for example, it can become dislodged and ineffective, such as when it ends up in the esophagus. If the tube is inserted too far into the trachea, however, past the carina, then the tube may only function to adequately ventilate one of the lungs, instead of both. This can lead to serious complications of its own. Thus, proper placement of the inserted end of the tube plays a major role in the intubation process.
Various techniques have been used in the past to attempt to ensure that the endotracheal tube lies in the proper location between the patient's vocal cords and carina at the end of the intubation process. One such technique involves placing a light at the inserted end of the endotracheal tube prior to intubation. The technique is based on the principle of transillumination, that a strong light can be transmitted through the cartilage and soft tissues of the neck. It was further discovered that when the light at the end of the tube was clearly visible through the patient's skin in the area of the sternal notch, then the inserted end of the tube was approximately halfway between the vocal cords and carina in most patients. The absence of a clear glow of illumination in this area usually indicates incorrect placement, such as in the esophagus.
Eventually, so-called lightwands were developed for use in the intubation process. Early lightwands comprised either a rigid or flexible copper wire with a battery at one end and a light at the other. When a rigid wire was used, it functioned as a stylet to stiffen and guide the tube into the trachea. The flexible wire typically has been used for nasotracheal intubation. Later lightwands were somewhat more sophisticated but not different in function.
While the development of the lightwand has been helpful in visualizing the airway during intubation and ensuring proper placement of the tube, the intubation technique still suffers from certain disadvantages. For example, sometimes the lightwand will become jarred or bumped during intubation and move from its position at the end of the tube. In these circumstances, the intubation procedure must be aborted and restarted, with the light at the proper location.
Moreover, once the lightwand is withdrawn from the tube after correct placement, there has been no reliable way to recheck the position of the tube at a later time. It has been known to use end-tidal CO.sub.2 measurements to monitor proper ventilation in an attempt to confirm, without visual evidence, that the tube is still in the trachea and not the esophagus. However, endtidal CO.sub.2 equipment may not be readily available, and patients in shock or in cardiac arrest may not be good candidates for qualitative measuring devices. Additionally, end-tidal CO.sub.2 measurements usually cannot detect right mainstem bronchial position, which can be a significant complication.
Other problems with known lightwands include the fact that the lights are directed in a forward manner such that the light tends to shine into the airway, rather than toward the patient's sternal notch. This makes the light difficult to see, unless the procedure is conducted in relatively low light conditions. This is especially true when intubation is being performed in bright sunlight, despite attempts to shield the patient's skin. As a result, proper placement of the tube cannot be readily confirmed, thus risking injury to the patient.
Still another problem with prior lightwands has been found to reside in the type and location of the switch used to illuminate the light. For example, the location of some switches has required that a second hand rotate the switch to the "on" position. This is time consuming, troublesome and inconvenient at best.
Accordingly, there has existed a definite need for an intubation device that ensures reliable and accurate placement of an endotracheal tube in a simple and convenient manner. There further has existed a need for an intubation device which, after intubation has been accomplished, enables fast and reliable checking of the tube placement at a later time. Finally, there has existed a need for an intubation device that can be operated using a single hand to intubate and illuminate the light, leaving the second hand free for other uses. The present invention satisfies these needs and provides further related advantages.